Imagine you have the undivided attention of three of the country's foremost health experts. Ask away.

The Panel

The Panel

Dr. George Kessler has been a practicing osteopath in New York for 35 years. He is a clinical instructor at Weill Cornell Medical College, an attending physician at New York-Presbyterian Hospital, and a consultant at the Hospital for Special Surgery.

Dr. Harry Fisch is a clinical professor of urology and reproductive medicine at Weill Cornell Medical College/New York-Presbyterian Hospital and the author of The Male Biological Clock.

Fitness expert Joel Harper trains celebrities (and regular people, too) at Joel Harper Fitness in New York. He also develops workout chapters for the You books by Drs. Mehmet Oz and Michael Roizen and has his own line of workout videos, Fit Pack.

Running, jogging, or walking — which is best for cardio and does the least damage to the body?

Running, jogging, or walking — which is best for cardio and does the least damage to the body?

Dr. George Kessler: Running can exacerbate any mechanical defect your body has. Walking at a moderately fast pace gives you 90 percent of all the aerobic benefit available and is less strenuous on your body.

Joel Harper: True, but if you run properly, damage should not be an issue. Think floating, not pounding. Pretend you're exercising on a sheet of glass, which will encourage you to use your muscles, not your joints. The bottom line is, what's going to get you sweating and building heart strength? Don't forget swimming, which is an underrated way to get your cardio in and use muscles differently.